Plug contactor



May 26, 1964 J. G- HATFIELD PLUG CONTACTOR Filed March 14, 1962 INVENTOR.

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United States Patent 3,134,633 PLUG CONTACTOR John G. Hatfield, Camp Hill, Pa., assignor to AMP Incorporated, Harrisburg, Pa. Filed Mar. 14, 1962, Ser. No. 179,686 13 Claims. (Cl. 3s9 217 This invention relates to plug contactors of the type used, for example, in plugboards for automatic computers, tabulators, accounting machines and the like, for completing selected electrical circuits to control the operation of the machine as desired.

It is among the objects of the present invention to provide an improved .plug contactor which is basically a manual-type, or one which cannot be accidentally withdrawn from the plugboard by push pressure on the nose of the plug, but can be easily withdrawn by pulling on either the wire to which the plug contactor is attached, or the shroud which encases the rear portion of the plug.

Another object of this invention is to provide an improved plug contactor of the type described above, which can be readily and easily changed to a semi-permanent, reusable type, or one which cannot be withdrawn from the plugboard either by push pressure on the nose of the plug contactor, or by pulling on the wire to which the plug contactor is attached, but can be easily withdrawn from the plugboard by manually, or with a suitable tool, depressing the spring elements by which the plug is retained in the plugboard while independently pushing on the plug.

Another object of this invention is to provide a plug contactor constructed of several basic parts, a simple alteration of which results in the plug contactor being either a manual or semi-permanent device, above described, as desired.

Another object of the present invention is to provide a positively-acting latch element which will not damage the plugboard or panel during its normal life when being inserted and withdrawn.

Still another object of this invention is that of providing a plug contactor which makes, between the wire to which it is attached and the plugboard contact, an electrical connection of low resistance, which is relatively invulnerable to the adverse effects of corrosive action, etc.

A further object is the provision of such a plug which is simple and economical in construction, and which may be easily assembled, but which is sufliciently rugged to withstand even careless use, and has a long useful life.

These and other objects of this invention will become apparent when the description is read in conjunction with the accompanying drawings wherein:

FIGURE 1 is a perspective view of a plug embodying the features of the present invention;

FIGURE 2 is a longitudinal sectional view of the plug of FIGURE 1, with the plug being shown in fully-inserted position in one of the openings of a plugboard;

FIGURE 3 is a longitudinal sectional view, generally similar to that of FIGURE 2, but showing the plug in partially-withdrawn position with respect to the plugboard;

FIGURE 4 is a fragmentary sectional view similar to that of FIGURE 2, but showing the plug fully withdrawn from the hole in the plugboard;

FIGURE 5 is a fragmentary transverse sectional view, taken along the lines 5-5 of FIGURE 2, and showing the latch detail;

FIGURE 6 is a fragmentary transverse sectional view, taken along the lines 66 of FIGURE 3, and showing the latch detail in depressed condition for releasing the lug; p FIGURE 7 is a longitudinal sectional view, generally 3,134,633 Patented May 26, 1964 similar to that of FIGURE 2, but showing the plug locked into the plugboard by a rearward push on the nose of the plug; and

FIGURE 8 is a fragmentary sectional view of another form of plug embodying the features of the present invention.

Referring to the drawings, the plug includes an outer sleeve 2, and the central portion 2a which is cylindrical and is adapted to be slidably received in one of the openings 4a of the plugboard 4, as shown in FIGURE 2. The rear central portion of the sleeve 2 projects from a forwardly-directed face 4b of the plugboard, and is provided in the present embodiment with a circumferential ridge 2b which serves as a stop to limit the longitudinal movement of the plug in the plugboard. The rearmost portion of the sleeve 2, which projects from a forwardlydirected face 4b of the plugboard 4 to a region of access, is provided with a wire barrel 20 adapted to receive a wire conductor, and to withstand a crimp or radial reduction in diameter onto the wire conductor, thus resulting in coldforging the wire barrel and the stranded wire conductor 6a into a substantially solid mass, thereby producing a good mechanical and electrical connection. The wire barrel 2c is integrally joined to the central portion 2a by a cylindrical portion 2a. Around the cylindrical portion 2d and the crimped wire barrel 2c is subsequently molded an insulating shroud or jacket 8 of plastic or the like, which also serves as a fingergrip to facilitate grasping of the rear end of the sleeve for inserting the plug into or withdrawing it from the plugboard. The insulating jacket 8 extends a substantial distance rearwardly from the point of connection between the wire 6a and wire barrel 20 to support the wire 6, and increase the resistance of the connection to fatigue caused by bending of the wire.

Extending forwardly from the central portion 2a of the outer sleeve 2 is a nose portion 2e, the forward end of which is rounded to facilitate insertion into a plugboard. The nose portion 2e is adapted for electrically conductive engagement with a spring contact 14 in the electrical device with which the plugboard is associated so as to form an electrical connection between the wire 6 and contact 14 and complete a selected circuit. The nose portion 22 is joined to the sleeve by a tapered transition piece 2g.

In the nose portion 22 is free-floatingly retained a nose member 10 which floats axially to the position shown in FIGURE 7. The central section 10b of nose member 10 is cylindrical and the forward end 10a is generally conical or rounded as shown. Integral with the central section 10b, on its rearward end, is an enlarged head which tapers up to a ridge with a rearwardly disposed tapered surface 10d on its rear end, as can be seen in the drawings. This arrangement permits limited longitudinal movement of the nose member 10 relative to the nose portion 2e of the sleeve, and prevents accidental withdrawal of the nose member 10 from the sleeve itself.

Disposed in the central portion 2a of the sleeve is a spring member 12 which contains the latch elements used to hold the plug in the plugboard. The spring 12 has a bight section 12c, out of which protrude catches 12d which lock in behind the forward inner surface of ridge 2b so as to hold the spring in place relative to the sleeve. The spring member is bifurcated with arms 12a which extend forwardly in the sleeve 2. These spring arms 12a are resilient, and near their forward ends, integrallyformed latch portions 12b project radially outwardly through slots 2f in the sleeve in position to be engaged behind a rearwardly-directed face 4c of the plugboard. The slots 21 extend into the central portion 2a of the sleeve 2 sufficiently to permit longitudinal movement of the latch portions 1212 (particularly in the embodiment shown in FIGURE 8) so that the spring 2 can travel far enough to come into engagement with the rear surface 10d of nose member 10 when it is in its forward-most position.

The forward and rearward surfaces of the latch portions 12b are properly beveled or tapered so that, as the plug is moved for insertion into or withdrawn from the plugboard, these inclined faces will engage the front or rear face of the plugboard, as the case may be, and cause the latch portions 12b to be cammed into the opening 4a of the plugboard.

Operation When the plug is inserted into the plugboard, the inclined forward surfaces of the latch portions 12b engage the forwardly-directed face 4b of the plugboard (FIG- URE 4), and cam the latch members into the opening 4a in the plugboard against the resistance of the resilient spring arms 12a to permit the plug to be inserted into the plugboard. The inner surfaces of the latch portions 12b are formed, as shown in FIGURE 5, so that the spring arms 12a will depress inwardly (FIGURE 6) to such an extent that the latch portions 12b are within the opening 4a in the plugboard, as is illustrated in FIGURE 3.

When the plug reaches its fully-inserted position, as shown in FIGURE 2, the latch portion 12b will spring back outwardly and engage behind the rearwardly-directed face 40 of the plugboard. With the plug in this position, a rearward pull on the jacket 8 will cam the rear tapered surfaces 12f against the front edges of hole 4a and result in the latch portions 12b entering into opening 4a, as shown in FIGURE 3. This will permit the plug to be withdrawn from the plugboard. Internally-beveled surfaces 12c of the latch portions 12b extend inwardly toward the center, and at their tips bend in a transverse direction, as shown at 12g in FIGURES and 6, so as to allow enough surface at 120 for the rearwardly disposed tapered surfaces 10d of the nose member 10 to cam the latch portions 12b outwardly. The bent tip sections 12g will then overlap in a scissor-like fashion when the latch portions are depressed, as shown specifically in FIG- URE 6.

When the plug is in the fully-inserted position, a rearward movement on the nose member 10 relative to the sleeve 2, such as is produced by a rearward push on the front end 10a of the nose member 10, causes the rearwardly disposed tapered surface 10d on the nose member to engage the internally beveled surfaces 12c of the latch portions 12b and cam the latch portions 12b outwardly so that the latch portions are locked behind the rear face 40 of the plugboard.

The above-described plug, however, can be easily adapted so as to be a semi-permanent plug, in that it cannot be pushed from or withdrawn from the plugboard without the aid of a tool or device to depress the latch portions 12b inwardly. This is accomplished by shearing off catches 12d and rendering the spring free to float a limited amount inside the sleeve 2. Shearing off of the catches 12d will allow the sleeve to move a limited amount longitudinally; therefore, any push pressure on the nose member 10 will bind surface 10d of the nose member against surface 12c of the latch portion and, in turn, lock the plug into the plugboard, as described above. Any rearward pull exerted on the jacket 8 will cause the spring member 12 to move forward relative to the sleeve until its internally-beveled surfaces 120 engage the rearwardly-disposed tapered surfaces 10d of the nose member 10 so as to cam the latch portions 12b outwardly. In this embodiment, the sleeve is free to move a limited amount longitudinally, as shown by small arrows in FIGURE 8.

It will, therefore, be understood that the plug shown in FIGURES 1 through 7 may be inserted into or withdrawn from the plugboard by movement of the sleeve; however, the plug may not be pushed from the plugboard by rear- Ward pressure on the nose member 10. It will also be 4 understood that the plug, shown in FIGURE 8, is a variation of that shown in FIGURES 1 through 7, but this plug may neither be pushed from the plugboard by rearward pressure on the nose member 10, nor may it be pulled from the plugboard by a pull on the wire to which it is attached.

It will also be seen that the plug, as shown in FIGURES 1 through 8, is formed of only four basic parts: the sleeve 2, which can easily be stamped from flat conductive metal, such as brass, and rolled to the configuration shown; the spring member 12, which also can be made from a flat stamping; the nose member 10, which can easily be formed on a screw machine or the like; and the insulating plastic shroud or jacket 8, which is molded onto the assembled plug after the wire lead is crimped thereinto.

It will, therefore, be appreciated that the aforementioned and other desirable objects have been achieved; however, it should be emphasized that the particular embodiment of the invention, which is shown and described herein, is intended as merely illustrative and not as restrictive of the invention.

I claim:

1. In a plug contactor, a sleeve having a support portion, a recess in the inside surface of the support portion, a U-shaped latch spring retained in said sleeve against axial movement by at least one radially projecting ear catching in the recess, said spring having latching means biased to protrude through a slot in the sidewall of said sleeve, a locking element disposed for longitudinal movement in said sleeve and engageable with said latching means to lock the latching means in latching position, said element including means disposed to receive forces applied to the forward end of the plug to move the locking element into engagement with said latching means.

2. In a plug contactor, a sleeve having a support portion and a contact portion, an opening in the forward end of the contact portion, a latch spring disposed in said sleeve with a pair of spring arms extending longitudinally and terminating in a pair of latching elements, said latching elements disposed such that their outward tips engage the device in which the plug is used, said latch spring biasing said latching elements to protrude through a slot in the sidewall of said sleeve, a locking element disposed for longitudinal movement in said sleeve and engageable with said latching elements to lock the latching elements in latching position, means disposed to receive forces applied to the forward end of the plug to move the locking element into engagement with said latching elements.

3. In a plug contactor, a sleeve having a support portion and a contact portion of smaller diameter than that of the support portion and joined to the support portion by a tapered transition section, an opening in the forward end of the contact portion, a generally U-shaped latch spring disposed in said sleeve and having a pair of spring arms terminating in latch elements biased respectively to protrude through a pair of opposed slots in the sidewall of said sleeve, a locking element disposed for longitudinal movement in said sleeve including a stem slidably carried in and protruding through said opening, and an enlarged, generally conical head disposed in said transition section, the rearward end of said head being tapered inwardly for wedging engagement with the latch elements to lock the latch elements in latching position upon relative movement of the locking element toward said latch spring.

4. A plug contactor of the type utilized to complete selected electrical circuits by engagement with a spring contact, comprising an elongated contactor sleeve having an outside surface of a configuration to slidingly fit within an aperture of a plugboard and support the contactor against radial displacement relative to such plugboard, said contactor sleeve having a bore therein, a wire receiving portion attached to said sleeve at one end adapted to be secured electrically and mechanically to a conductor wire, an elongated nose portion substantially smaller in cross-sectional dimension than said sleeve and fixedly attached to and supported by said sleeve at the other end thereof opposite said wire receiving portion, said nose portion including an outside surface defining an area for engagement with a spring contact to establish an electrical path from the spring contact through said nose portion and said sleeve to said conductor wire, said nose portion including an opening at the end thereof opposite the attachment with said sleeve and a bore extending from said opening through the elongation thereof to join said sleeve bore, at least one further opening in said sleeve near the end thereof attached to said nose portion, a spring member supported in said sleeve bore with said latching means having an arm extending longitudinally along said sleeve with a latching means integral with said arm, said spring member being driven by said spring member in a radial direction to extend from said further opening and engage said plugboard to inhibit said contactor against axial movement relative thereto, a nose member slidably supported in said nose portion bore having one end extending from said opening such that axial forces applied thereto drive the other end into a position to block said latching means from inward travel and thus hold said latching means in an outward position extending through said further opening to prevent said contactor from being pushed from said plugboard.

5. The contactor of claim 4, wherein said spring member is secured within said sleeve against axial movement such that withdrawal forces applied to the plug contactor wire receiving portion operate to cam said latching means inwardly within said sleeve to permit withdrawal of said contactor from said plugboard.

6. The contactor of claim 4, wherein said spring member is free for axial movement and said further opening is of a length to permit forward movement of the spring member whereby said latching means is blocked by the said other end of the nose member from inward movement to prevent said plug contactor from being pulled from said plugboard.

7. The contactor of claim 4, wherein said spring member is free within said sleeve for limited axial movement therein and said latching means includes a longitudinal dimension relative to a longitudinal dimension of said further opening to permit a short sliding movement axially, such that pulling forces imparted to said contactor sleeve displace said latching means forwardly to engage said other end of said nose member and thereby become locked against further inward travel to hold said contactor against being pulled out of the plugboard.

8. In a plug contactor, a sleeve having a support portion and a contact portion, an opening in the forward end of the contact portion, a latch spring disposed in said sleeve with a pair of spring arms extending longitudinally along said sleeve with a least one of said arms terminated in a latching element, said latching element disposed such that its outward tip engages the device in which the plug is used, said latch spring biasing said latching element to protrude through a slot in the side wall of said sleeve, a locking element disposed for longitudinal movement in said sleeve and engageable with said latching element to lock the latching element in latching position, means disposed to receive forces applied to the forward end of the plug to move the locking element into engagement with said latching element.

9. In a plug contactor, a sleeve having a support portion and a contact portion of smaller diameter than that of the support portion and joined to the support portion by a tapered transition section, an opening in the forward end of the contact portion, a generally U-shaped latch spring disposed in said sleeve and having a pair of spring arms, at least one of which is terminated in a latch element biased to protrude through a slot in the side wall of said sleeve, a locking element disposed for longitudinal movement in said sleeve including a stem slidably carried in and protruding through said opening, and an enlarged,

generally conical head disposed in said transition section, the rearward end of said head being tapered inwardly for wedging engagement with the latch element to lock the latch element in latching position upon relative movement of the locking element toward said latch spring.

10. In a plug contactor, a sleeve having a support portion and a forward contact portion, a U-shaped spring member disposed in said support portion with the bight of the U extending oppositely of the contact portion and with a portion of said spring member engaging said sleeve to limit the axial movement of said spring member relative to said sleeve, a slot in the side wall of said sleeve support portion, said spring member having latching means driven thereby to protrude through said slot and biased outwardly by said spring member, a locking element disposed for longitudinal movement in said sleeve contact portion and engageable with said latching means to lock the latching means in latching position, said locking element including means disposed to receive forces applied to the forward end of the plug to move the locking element into engagement with said latching means.

11. In a plug contactor construction adapted to be locked against being pushed from the aperture of a plugboard, the combination comprising a conductive sleeve member having a support portion of a diameter to fit within a plugboard aperture, a forward contact portion extending from said support portion and of a substantially smaller diameter, the said contact portion including a bore of substantially constant diameter along its length, at least one slot in the side wall of said sleeve proximate said contact portion and at one end of the support portion, a spring member disposed in said support portion including at least one arm supported for cantilever movement generally parallel to the longitudinal axis of the contactor and having at the free end thereof a latching element biased radially to protrude through said slot, a nose member having a stem portion fitted within the bore of said contact portion with one end thereof extending out from said contactor and the other end thereof attached to a head having a cam surface thereon, the nose member having along the length from the end extending out of said contactor to the end having a head thereon a diameter less than the bore of said nose portion such that the nose member is freely slidable inwardly in an axial sense but is locked against withdrawal by said head member, the said nose member operating to receive forces applied to the forward end of said contactor to drive the said cam surface to engage said latching element and block the latching element from inward radial travel to preclude the contactor from being pushed out of a plugboard aperture.

12. In a plug contactor of the type inserted in a plugboard, a sleeve having a support portion, a forward nose portion having a nose member positioned therein for sliding movement with one end thereof extending forwardly of said contactor, a spring member positioned by said sleeve with at least one end forming a latching element biased to extend radially outward of said sleeve but movable radially inward through a slot in said sleeve, the other end of said nose member and the said latching element being positioned relative to each other such that longitudinal forces applied to said nose member drive the other end thereof to block inward radial travel of said latching element to prevent the contactor from being pushed out of a plugboard, the spring and latching element being slidably free relative to said sleeve to be driven forward by a pull applied to the contactor to a point wherein said latching element engages said nose member other end and is thereby blocked from further inward radial travel to prevent said contactor from being pulled from a plugboard.

13. In a plug contactor, a sleeve having a contactor support portion and a contact nose portion, a nose member secured in said nose portion for sliding movement axially therealong and including a head member disposed in said support portion and an end opposite thereto protruding from said nose portion, a spring memher having a cantilevered arm carrying a latching member positioned in said sleeve with said latching member biased radially by said arm to protrude through a slot in said sleeve, the nose member having a forward position with said head axially disposed from said latching member and a rearward position engaging said latching member to block inward travel thereof, the said spring and latching member being fixed against axial movement to a point of engagement with said head in its forward position.

References Cited in the file of this patent UNITED STATES PATENTS Watts Nov. 23, Schelke et a1 May 29, Sesny et a1. Ian. 29, Francis Apr. 2, Watts Apr. 14, Sitz Sept. 8, Clouthier Sept. 26, Watts Apr. 9,

FOREIGN PATENTS France Aug. 24, 

1. IN A PLUG CONTACTOR, A SLEEVE HAVING A SUPPORT PORTION, A RECESS IN THE INSIDE SURFACE OF THE SUPPORT PORTION, A U-SHAPED LATCH SPRING RETAINED IN SAID SLEEVE AGAINST AXIAL MOVEMENT BY AT LEAST ONE RADIALLY PROJECTING EAR CATCHING IN THE RECESS, SAID SPRING HAVING LATCHING MEANS BIASED TO PROTRUDE THROUGH A SLOT IN THE SIDEWALL OF SAID SLEEVE, A LOCKING ELEMENT DISPOSED FOR LONGITUDINAL MOVEMENT IN SAID SLEEVE AND ENGAGEABLE WITH SAID LATCHING MEANS TO LOCK THE LATCHING MEANS IN LATCHING POSITION, SAID ELEMENT INCLUDING MEANS DISPOSED TO RECEIVE FORCES APPLIED TO THE FORWARD END OF THE PLUG TO MOVE THE LOCKING ELEMENT INTO ENGAGEMENT WITH SAID LATCHING MEANS. 